The use of machines for filling containers with free flowing powdered or granular material is well known. These powdered or granular materials include a broad range of food products, including, milk products, condiments, tea, coffee, sugar, cocoa, rice and seeds, as well as a general line of chemicals, including, cleaners, lyes, crystals, and the like. Machines of this general type have found a wide range of acceptance in the food, chemical and cosmetic industries, for packaging all manner of dry materials. A certain machine which has found wide acceptance is disclosed in U.S. Pat. No. 3,967,662, entitled, "Container Filling Apparatus", which issued July 6, 1976, wherein Graeme W. Warner, of Hinsdale, Ill. is the patentee. The operation of the patented machine has been widely accepted as being satisfactory; however, there is a problem when the machine is used with certain containers which do not have a uniform heighth from the exterior bottom portion of the container to the interior bottom portion of that container. The problem is oftentimes more pronounced with glass containers than with other containers, such as, plastic or metal containers.
Most glass containers are manufactured by a blow-molding process wherein molten glass is first placed in a parison mold for initial blowing, and then is further blown in a second mold for the final blowing of the glass container to the finished configuration. Since the container is made by a blow-molding process, the thickness of the bottom of one glass container is not always the same as the thickness of the bottom of another glass container made by the same operation at the same time. This variance in thickness of the bottom of glass containers creates a problem in filling those glass containers. The filling machine shown in Warner U.S. Pat. No. 3,967,662 may be built in any one of a number of forms wherein the machine may fill anywhere from twenty containers per minute to three hundred containers per minute, or sometimes even faster. It may be appreciated that as the speed of the filling operation is increased from one container each three seconds to one container each one-fifth of a second, the glass containers are moved up toward the measuring flasks at a rapid rate. The result is that if there is an attempt to adjust the distance between the bottom of the filling flask and the top of the conveyor carrying the containers to a point where the filling flask just touches the bottom of the container, the variance in the thickness of the bottoms of the glass container results in the bottoms of the containers striking the measuring flasks and breaking out bottoms of those containers. This is an undesired result.
In order to avoid the breaking of the bottoms of the containers, and to accommodate the varying sizes of the containers, the distance between the bottom of the measuring flask and the top of the conveyor is adjusted so that there is always a space between the bottom of the measuring flask and the top of the thickest bottom of a container. An inspection of the drawings of the aforementioned patent, especially FIGS. 1 and 5 of that patent, shows how the bottom of the flask is spaced from the bottom of the container. This results in granular material flowing out from under the bottom of the measuring flasks and over the top of the bottom. This flow of material is referred to as flushing. The amount of flushing which occurs is dependent upon the amount of space between the bottom of the flask and the top of the interior surface of the bottom. The type of material which is being filled also has an effect on the amount of flushing. It may be appreciated that in order to make certain that a container is filled with the minimum amount of material to satisfy the shown amount on a label, it is necessary to adjust the filling machine so that the full amount of material is delivered to the container when there is a minimum amount of flushing. When there is additional flushing, there is an overage of material in the container. It may further be appreciated that when there are three hundred containers per minute filled in a given machine, the overage can result in a substantial over delivery of material efficient than is desired.
The flushing problem has been with the filling industry for many years, but no satisfactory solution has been found heretofore. It is the principal object of the present invention to provide an improved measuring filling flask which eliminates the problem of flushing and allows a container to be filled with the correct amount of material.